Regulator



Patented Aug. 3, 1943 2,326,039 REGULATOR Joseph F. Kovalsky, Turtle Creek, Pa., assigner to Westinghouse Electric & Manufacturing Company, East Pittsbur Pennsylvania gh, Pa., a corporation of Application March 1, 1941, Serial No. 381,337

(Cl. 2do-101i) 2 Claims.

This invention relates to voltage regulators.

In regulators of the rheostatic type, a switching apparatus is somtimes employed for cutting in or shunting the regulating resistance of a control or energizing circuit. Usually an electroresponsive device, responsive to changes in voltage which it is desired to regulate, is utilized for actuating the switching apparatus. In .the usual rheostatic regulator, in order that the regulating device remain stationary at a particular position corresponding to a. particular effective value of the regulating resistor, it is necessary that there be a slight variation between the pull curve of the electromagnet and the load curve of the apparatus which opposes its motion. Otherwise the moving element of the regulator would remain stationary in any position instead of in one position only fora given energization of the electroresponsive device and a. corresponding pull on the arma-ture.

Heretoiore, the degree of Ysensitivity of the rheostat regulators has been adjusted ,by varying the pull on the spring ropposing the force of the electroresponsive device. When the pull on the spring is varied, the current through the electroresponsive device required to balance the spring force is changed. These changes reduce the range in which an ellective change in the regulating resistor canbe made for regulating for a particular voltage.

Where rheostatic regulators are employed with low voltage (20,150 volts) direct current generators in which current of the order of 4 to 5 amperes is encountered the 4load curve of the component parts of the regulator is substantially linear over a large portion of the curve and the difference in the load curve and the pull curve is not so marker'- Whereiy the degree of sensitivity desired is maintained over a wide range of the curves giving a fairly wide Working range for the regulator.

However, Where the rheostatic regulators are employed with high voltage (100 to 44() volts) alternating current or direct currentgeneratorsV essary to obtain a substantially linear sensitivity over a wide working range of the regulator.

An object of this invention is to provide for compensating for the changes -in the magnetic pull applied in effectiefr a regulating operation of a regulator to give the regulator predetermined Characteristics.

A further object of this invention is to provide in a regulator anelectroresponsive device in which oppcsingrorces are so provided to oppose zthe magnetic pull as to give the regulator a substantially linear sensitivity over a predeterminedk Working range.V

Another object l'iis invention is to provide in a regulator an electroresponsive device and a plurality of biasing means associated therewith ier opposing the magnetic pull of the electroresponsive device to give .the regulator a substantially linear sensitivitover a predetermined working'range.

ther objects of this invention will become apparent from the following description when taken in conjunction with the accompanying drawing, in which:

Figure l is a view in elevation of a regulator embodying the features of this invention;

Fig. 2 is a schematic diagram illustrating the apparatus of this invention in a control systern;

Fig. 3 is a graph, the curves of which illustrate the sensitivity of :the regulator of this invention in terms of travel of the moving parts thereof; and

Fig. 4 is a view taken along the line IV-IV of Fig. l illustrating a detail of the apparatus there shown,

VReferring to Figure l, there is illustrated the regulator i8 of this invention. The regulator I!) comprises a plurality of component operating parts such the resistor I2, the primary control device I4 and the electroresponsive device IS operatively associated together.

The resistor I2 may be of any suitabln type and is preferably of the pile type described and claimed in the copending application of C. C. Whittaker, Serial No 312,517, filed January 5, 1940, and assigned to the assignee of this invention, which applicationy became Patent No. 2,249,326 on July 22, 1941. The resistor I2 is carried between suitable brackets I8 and 20 mounted on a panelboard 22 by any suitable means such as the bolts 24.

'Ifne primary control device I4 is preferably of the type described in copending application of C. R., Hanna et al., Serial No. 203,876, led April more fulli7 which maybe adjustable.

of the contact buttons 345.

With the leaf spring conducting members held in this position Vby the brackets 38, one end of each of the conducting members 2E is connected either by an exten-'- sion thereof or by suitable'leads 32 to different sections of the resistor unit l2, the connections beingV so madethat the conducting members 2t in the assembled stack are connected progressively to successive sections of the resistor unit I2. The other end of the conductorimembers 2B may be termed the free ends and carry contact members "or buttons 3d. The conductor members 25 are normally self-'biaseditoward the left as shown in Fig. '1, so that the ends thereof are adapted to engage an inclined surface 3G of a stop 38 in sequence las theY conductor members 26 are moved to the left to permit the separation In addition to the sloped surface Vthe stop is also'provided with an upright stop portion 46 at its lower righ*- hand edge for cooperating, as will be explained more fully hereinafter, to equalize the Contact .pressure on the contact buttons 3d carried by the conductor members 2t.`

D gli,

."lIhe electroresponsive`V device Eli may be of any A suitable type and in this vembodiment is illusscrew Bil carried in a support 62 of non-magnetic material on the leg 48 ofthe core member, the other end of the spring 5i! being secured to a lug 6d carried above the pivot point of the lever 52. As illustrated, the main spring 53 is disposed at an angle of less than 90 to the lever 52 for any position of the lever'as itmoves through its arc of movement in actuating the conductor members 2t of the primary controlpdevice Iii. By

mounting the spring 58 in this position, the pull on the lever 52 by the spring 5S is a non-linear pull for any of the operating positions of the driving member 525. This positioning of the main spring SiS so changes'the force acting on the driving member E@ as the driving member 553 approaches its furthermost position in actuating the conductor members 2d towards the right that the force-appliedthereto opposing the magneticY pull of the electro-responsive device l5 is de- Y creased to give a more linear sensitivity curvefor that portion of the operating cycle ci the regula- The forceof the Ymain spring 58 can vbe ad'- tor. justedby adjusting the position of the screw 60 in its support S2.

' Associated with the electroresponsive device i6 and disposed to be engaged by the driving member 5@ is a spring member t@ carried on the end of an adjustable screw G3 which is carried on the panel 22 by the support it.

adjusted thereon for changingy the eiective length of thespring Vwhich extends beyond the trated asco'mfprising the substantially U-shaped l core member having legs l2 and E8, the energiz-A ing'winding l5 carried on the leg 42 of rthe core member', Vandan armature '56 associatedtherewith. The electroresponsive device I6 is mounted on the panel 22 any suitable means such as a screw or bolt 5l through a part of the frame.

In this embodiment, the armature l'o comprises a portion of the actuating member for driving the contact members 26 of the primary control device l.. The armature 46 carries an insulating driving member 5d at its lower end disposed to engagethe conductor membersZS at their lower end toactuate the conductor members 2G Yprogressively away from the sloped surface 36 of the stop 38 until they Contact the upright stop .49. In this position the pressure on the contact buttons '34 is equalized.

wardlyextending projections at the end of the leg of the core member by means of a substantially U-shaped springmember 5e as illustratedin Fig. 4. As illustrated, the en dsof the legs ofY the member 5 areV secured to the upwardly eX- tending projections at the end of the leg 48 and l the' armatureV 45 is secured to the yoke portion and provides a substantially frictionless support` for tnefdriving member Eil. Y A stop 5'5 of non-V magnetic material is provided for engaging the end of the lever 52 to limit the movement of the The armature 46 forms an extension of a substantially L-shaped lever member 52 and is pivctally mounted to the up-V end of the screw 68. As illustrated, Ythe* free end of the spring 66 is disposed to be lengaged by the driving member '5d only after the driving member has been actuated by the electroresponsive device a predetermined distance through its Y arc of movement towards the left to eifect a separation of a predetermined number of the contact buttons 34.

YBy positioning the spring 55 in this manner, it cushions the driving Vrnernber and prevents a quick snap action of the drivingV member to effect a separationA of allcf the contact buttons o Sil as the magnetic pull of the electroresponsive device I6 increases. This isquite evident for as the armature Z moves in a clockwise direction about its pivot due to the pull of the electroresponsive device I5, the armature d@ approaches the core member l2 andthe magnetic pull on'the armature it becomes stronger. With the spring, member 67B positioned to engage the driving memberv 5i! at a predeterminedV point in the arc of movement of the driving member, an additional force is suppliedrforV opposing the magnetic pull of the electro-,responsive device i5. The position of the spring 66 and consequently the point at driving member 553 in a counterclockwise'directic-n aboutrthepivot formed bythe spring 54. Amainlspring 5S is provided for opposing the magnetic pull on the armature 46.

y l y Y Y The mainv ,y spring 58v is secured at one end to an adjustable which the opposing force is applied to oppose the Y pull of the electroresponsive device I5 can be adjusted by Yadjusting the position of' the screw 68 in its support '58.

The spring 66 thus cooperates with the spring EAB which also opposesrthe vmagnetic pull on the armature it to prevent a quick change in the sensitivity curve of the apparatus as the armature approaches lthe core` member i2 of the The sensitivity curve Y electroresponsive device I5. in terms of rtravel of the armature il@ is thus prevented Vfrom dropping off fast Vand a substantially linear curve for this'pportion of theoperating characteristics Vof the regulator is thus obtained, As will be understood even with'the springs 66 and 58 disposed to cooperate as described, when Y the armature Mi reaches a Vpredetermined position in its 'arc of movement, the magnetic pull of the t Y The spring 66 isV preferably threaded on the screw 63 and can'be telectroresponsive devicer 'IE Vbecomes so strong -that even with-the spring 66 present, ra quick `change inthe sensitivity curve in terms .of travel of the moving parts kof the apparatus is encountered. 'Likewise for an extreme position of the driving 4member 50 at the right-hand portion of its .arc of movement, as the magnetic pull becomes smaller the relative force of the s' ring 58 .becomes sufhciently strong to v effect a quick change in the .right-,hand portion of the sensitivity curve of the apparat-u rReferring to Fig..2, there is illustrated a system in which Vthe apparatus fof 'this invention is con'- vnected to provide the desired control vof Voltage. As illustrated, van alternating current generator 12 is provided for supplying power to any suitable load, not shown. The generator 12 comprises the armature winding 1d and the field wndiligs 18. The field windings 16 are disposed to be energizecl by an exciter 18 'driven from any suitable 4source of `power, not shown, 'and the resistor element I2 `of the regulator of this invention is illustrated as being connectedv in series circuit relation with the field vwindings 16. The electroresponsive device I6 of the regulator of this inveii-v tion is so disposed and connected that the mag- `netic winding 44 thereof is energized in accordance with a change of the voitage across the armature 14 of the generator i2, a rect' 20 being provided in circuit therewith for providing direct current excitation of the winding M. The primary corrtrol devicek I4 .is illustrated 'ith the conductor members 2B connected by the Yleads 32 to diierentsections of the resistor unit I.

Althoughillustrated in both Figs. 1 and 2 an extreme condition of the circuit, the electro- `responsive device I6 and the primary control device I4 are usually so arranged that for given voltage across the generator armature il, the magnetic pull ofthe electroresponsive device I6 to actuate the driving member 4Q is balanced by the force of the spring 58 to maintain the driving member in such a position as to permit a portion of the conductor members 25 to be spaced vapart, thereby electrically connecting a number of the resistor sections of the resist-oiv I2 i cuit with the field windings 16 of the generator 12.

In operation, assuming that the `field windings -16 of the generator 12 is`v energized to provide a predetermined operation of the generator 12, a portion of the resistor unit i2 being` in circuit therewith, if for any reason the load tuppiied by the generator 12 changes thereby eiecting a change in the voltage across the armat fic winding 14, a corresponding change is Ve-iiected in the Yenergization of the winding 44 of the electroresponsive device I6.

If the change in the voltage across the armature 14 is an increase, the energization of the winding 44 is increased and thedriving member 50 is actuated in a clockwise direction about its pivot 54 to permit the conductor membe4 successively engage the sloped stop 33 and cut in additional-sections of i sister l2 in circuit with the nein winding is of the generatorn. If this addition of the sections of the resistor l2 is insulicient to reduce the' energizatio-n of the field winding 'i5 to a value where the voltage across the a 1li a desired value, then the driving me i actuated further until it engages the spring member 66.

:I-and rprevent-aqulck dropping orf ofthe sensi- `tivity -curve to maintain Vit substantially linear 'over 'the lower portion -of the predetermined vworking range for a predetermined movement of the driving member 59. If the cutting in of `the sections of the resistor unit 2 over this range .is still'ineulilclent to effect the necessary decrease .in the energlzation of the field winding i6, then 'it is Sioundithat the -magnetic pull of the electromagnetic device 'I6 becomes so strong as to overcome the opposing vforce of springs 56 and 58 and-effect a quick change in the sensitivity curve yillustrated vin Fig. 3. Under these conditions the driving 'member /50 is actuated to effect a quick separation of `all of the `Contact buttons 34 of the conductor lmembers vIi and insert all of the resister !2jin 4circuit with the field winding 16. This is knownas field reducing in the operation of regulators and control circuits and is illustrated by vtheriet-liand portion of the sensitivity curve of Fig. 3.

however, the change in the voltage across the :generator A'armature 14 is a decrease instead of an increase, then the winding 44 of the electrorespcnsive device I6 is correspondingly deenerg'ized and the force of the spring 58 accordingly actuates the vdriving member 5i) through 'its arc of movement in the counterclockwise direction about its pivot 54 to eiectively actuate successive lconductor members 26 from engagement with the stop to shunt additional sections of the resistor i2 from circuit with the field windings 16 to increase the energization of winding 'i5 and conseouenty effect an increase in the voltage across the genera-tor armature 1d. It is to be noted that as 'the driving member 53 moves in the countercrcclnvise direction, `the pull of the spring 58 ich 'at ail times is non-linear with respect to the movement of the driving member 50 is decreased scme'what due 'to the change in the lever arm eiected by mounting the spring in the manner described. By providing for decreasing the pull of spring 58 in this manner the right-hand portion of the sensitivity curve of the working range illustrated in Fig. 3 is maintained substantially linear with respec to the desired working range of the apparatus. However, if the movement ol the driving member 50 towards the right is insumcient to eiect the desired energization of the eld winding 16, the winding 45 of the electroresponsive device becomes further deenergized with the result that the magnetic pull on the driving member 53 is further decreased and the effective force of the spring 58 is consequently greatly increased at a predetermined position in theV arc of movement of the driver member 5B to eiiect a quick closing of all of the Contact buttons S to shunt all of the resistor I2 from circuit with the eld windings 16. This action is known as eld forcing to effect a. quick increase windings. The change in he sensitivity curve by this action is clearly illustrated in the curve of Fig. 3, the force of the spring 58 effecting a quick operation of the last few conductor members .28 to shunt all of the sections of the resistor I2 from circuit with the eld winding 16. Under these conditions, all of the conductor members 25 are biased against the stop 49 giving an equalized contact pressure between the contact buttons 34 carried by the conductor members 26. With the field forcing the energization of the field winding 16 is so increased as to quickly restore the desired voltage across the armature 14 of generator 12 and consequently effect a in the cnergization of the eld change in the energization'of the winding il!! of the electrcresponsive device it to eiect a change in the setting of the primary control device l@ and return the contact conductor members 25 to their normal operating position.

In describing the foregoing apparatus and op-V eration nothing has been said as to the force of the self-biasing conductor Vmembers 2S. It is, of course, to be understood that the self-biasing conductor members 2S also apply a force which opposes the force ofthe springs tt and 5S. 'However, this self-biasing force is so small that for purposes of describing this invention in terms of the spring members 58 and 55 cooperating to oppose the magnetic pull of the electroresponsive device it, it can be neglected, adjustments naturally being made in the setting of springs 5S and 6G to oiset the force of the self-biasing conductor ,members 26. l Y Y Y With the apparatus of this invention it is possible to provide a'regulator which has a substantially linear sensitivity over a predetermined wide working range. With such apparatus it is possible to emciently'regulate the voltage of small direct current and alternating current generators while at the same time retaining the desirable features of eld forcing and eld reducing. Further, the desired regulation can be obtained by employing a primary control Ydevice .which has a comparatively few steps for effecting the desired regulation. in addition the regulator is constructedy of light weight elements which V.can be conveniently and efciently mounted in a V,small space.V This` invention therefore provides a taken yinV conjunction with the sensitivity obtained` renders the regulator oi this invention hignly desirable for service. I

Although this inventionV has been described with reference to a particular embodiment thereof, it is, of course, not to be limited thereto except insofar as is necessitated by the scope Vof the appended claims.

lf c] im as my invention:

in a regulator for controlling electric quantity' over a predetermined Working range, a control device comprising, in combination, a plnralityof contact members normallybiased to open'circuit position, electromagnetic means disposed kfor actuating the'contact members in sequence, the electromagnetic means comprising a core member, an energizing winding carried by the core member, and a pivotally mounted armature member disposed for vmoven'xent through a predetermined arc about an axis Vfor driving tie of the armature as it' member in one direction'about its axis to sequenabout its axis, and another biasing means disposed in the path ci movement of the Varmature member I for engagement therewith after the Yarmature member is actuated a predetermined `distance in said opposite direction to allow only a part oithe contact members to separate, the two biasing means cooperating with the energizingwinding carried by the core memberl to provide a substantially linear sensitivity or the control deviceembodying theV variable air gap over a predeterminedworking range.`

2. n a regulator for controlling an electric quantity over fa predetermined working range, a control device comprising, a plurality of selibiased elongated circuit controlling members ar ranged with one end of each insulated from and supported in iiXed relation to each other, the other ends ofthe members being free to '.move, Contact members carried by the free ends, a stop having a contact surface at an angle to the generaly direction of the elongated members disposed torsspacing the free ends of the members When they seat thereon under the self-biasing iniluence and to permit unrestricted movement of the elongated members away from the stop, an-

-other stop associated with the'elongated members to limit their Vmovement awayfrom the `angular stop and. to insure equalize'd Contact pressure between the contact members under predetermined conditions,electromagnetic means disposed for actuating the Acircuit controlling members in sequence away frornthe angular stop, the electromagnetic means comprising a `core Vmember, ran energizing Winding carried'by theY core 'memben and a pivotally mounted armature ,Y

member disposedior movementthrough a predetermined arc about an axis for driving the circuit controlling members, the core member and 'the armature memberfhaving a variable air gap throughout the predetermined'arc of movement Y axis to sequentially actuatev the Ycircuit ycontrol'- .ling members to circuit closing positions, vthe Winding carried by the core membereiecting the actuating of the armature member inthe opposite direction about its axis, and anotherbia'sing l means disposed in theV path of movement ofthe armature member forY engagement therewith alter the armature member is Yactuated a predetermined distance in said opposite'direction to 'allow only a part ofthe circuitJ controlling rn'ernbersl to separate, the two biasing means cooper- 'ating'. with the energizing Winding carried lby the core member and thesel-biased circuit controlling members to provide a substantially linear sensitivity, of the control device embodying the variable air gap over a predetermined working range.v f

JOSEPH F. KOVALSKY. 

